Wire and Tape Method
As with the top tip of the corsage, I use smaller leaves on the bottom. The pittosporum is doubled almost completely over itself.
This way the leaves point downward, giving a finished polish to the look.
Here's now a front view of the corsage. You can see what an advantage it is, to have every flower head, leaf and ribbon loop wired so you can place them exactly where you want them without breakage.
Here is the bottom side, the leaves that are bent downward concealing it nicely.
Here is a side view of the corsage. Look for any gaps you need to fill.